The present invention relates to a process for the preparation of a chemically substantially pure thymic hormone, designated as THF, to the purified substance as novel composition of matter, to pharmaceutical preparations containing said purified thymic hormone THF as active ingredient and to processes of immunosupportive therapy and to other methods of treatment making use of said novel purified composition of matter.
It is known for some time that the impaired capacity of neonatally thymectomized (NTx) animals to reject skin grafts and to induce graft-versus-host (GVH) response are partially restored either by implantation of cell-impermeable diffusion chambers containing thymus tissue, or by injection of cell-free thymic extracts. It has been shown that extracts containing the thymic hormone increase the cytotoxic reactivity of lymphoid cells against syngeneic tumors in vitro and in vivo, see Trainin et al, J. Exp. Med., 138: 1521 (1973).
In view of the recognition of the important and valuable characteristics of the thymic hormone THF, it was considered to be of considerable advantage and value to try and obtain this in a chemically purified form, so as to make it possible to use it in medicine, as well as in research without the complications and drawbacks of preparations wherein such hormone is combined with various other constituents, such as proteins, hormones, etc. Only a purified substance can be used with a minimum of side-effects, and only a purified substance can be standardized so as to make possible an accurate dosage of such substance in medical applications.